ASYNCHRONOUS REMOTE COPY SYSTEM AND STORAGE CONTROL METHOD

摘要

In the disclosed asynchronous remote copy system, if a first storage device has stopped, it is determined which of an update number comprising a journal that has been recently reflected in a second storage device and an update number comprising a journal that has been recently reflected in a third storage device is newer. Then, by a new storage device comprising an update number that has been determined to be new, it is determined whether or not there are one or more difference journals from a journal comprising an update number following an update number that was not determined to be new to a journal comprising an update number that was determined to be new. If the result of the determination is positive, one or more difference journals are copied from the new storage device to an old storage device which was not the new storage device among the second and third storage devices. In the old storage device, the one or more difference journals are reflected in order of update number in the data volume within the old storage device.